Abstract Energy is efficiently extracted from geothermal wells by flashing a portion of the hot fluid from the well into steam and using the steam and the hot fluid to heat an operating fluid in a closed system wherein the temperature and pressure are such that the operating fluid vaporizes and the fluid has sufficient superheat to avoid condensation when expanded in a prime mover such as a gas expansion gas turbine that has at least 75% conversion efficiency. Additionally, the operating fluid as a vapor has a specific heat that is at least 50% of the specific heat of the operating fluid as a liquid over the temperature range of 100° F. to 250° F. under the operating pressures of the process. Instead of using the steam to heat an operating fluid, it may be applied directly to a steam turbine. Additionally the steam may be washed before application to the turbine.
A process for converting naturally occurring heat energy from within the earth carried by a hot fluid consisting of steam and water to mechanical energy comprising the steps of: flashing a portion of the fluid to steam; recovering the heat energy in the steam; passing the water in heat exchange relationship with an operating fluid having a critical temperature below the input temperature of the water; superheating the operating fluid with the heat from the water; expanding the operating fluid in a power extracting gas expansion device; condensing the operating fluid after extraction; and repeating the steps in a continuous process.
Claim 2
Dependent Claim
101 words
A process for converting naturally occurring heat energy from within the earth carried by a hot fluid consisting of steam and water to mechanical energy comprising the steps of: flashing a portion of the fluid to steam; recovering the heat energy in the steam; passing the water in heat exchange relationship with an operating fluid having a critical temperature below the input temperature of the water; superheating the operating fluid with the heat from the water; expanding the operating fluid in a power extracting gas expansion device; condensing the operating fluid after extraction; and repeating the steps in a continuous process.
Claim 3
Dependent Claim
52 words
A process in accordance with claim 1 wherein the operating fluid has a specific heat as a vapor in the temperature range of 100° F. - 250° F. that is at least 50% of the specific heat as a liquid over the same temperature range under the operating pressures of the process.
Claim 4
Dependent Claim
35 words
The process in accordance with claim 2 comprising the further step of maintaining the pressure of the operating fluid at the input to the gas expansion device above the critical pressure of the operating fluid.
Claim 5
Dependent Claim
16 words
The process in accordance with claim 1 wherein the steam is passed through a steam turbine.
Claim 6
Dependent Claim
20 words
The process in accordance with claim 1 wherein the steam is passed in heat exchange relationship with the operating fluid.
Claim 7
Dependent Claim
40 words
The process in accordance with claim 5 comprising the further step of combining the steam after passing in heat exchange relationship with the operating fluid with the water and passing the combination in heat exchange relationship with the operating fluid.